The overall goal of Project 3 is to evaluate how tobacco policies influence the design of cigarettes and the chemical properties of the smoke they produce, and what effect(s) these developments have on smokers' perceptions and behaviors. The study uses a longitudinal design, multiple country controls, and an Elasticity/Compensation Model, which recognizes that 1) cigarette companies respond to policy mandates for design changes by implementing features that maintain smoker acceptability and 2) smokers perform compensatory behaviors to maximize their satisfaction from smoking. We wilt use data from an international repository of cigarettes we develop and from the International Tobacco Control Policy Evaluation Survey (ITCPES). We will sample popular and unpopular brands in four categories of tar delivery (very low, low, medium, and high), as well as potential reduced exposure products and emerging brands. The cigarette brands will come from eight countries: the four ITCPES countries (Canada, United States, United Kingdom, and Australia); the two ITCPES expansion countries (Malaysia and Thailand); and Greece and the Czech Republic, both of which have time to comply with the EU performance standards. Products will be analyzed at the CDC's Tobacco Analysis Laboratory. The ITCPES surveys will include items on perceived relative hazard from various brands, product acceptability, brand switching, and other relevant constructs. CDC scientists will assess design features such as tobacco blend, % filter ventilation, paper porosity, and )ressure drop for each brand. Smoke chemistries will be assessed under various machine regimens and include tar, nicotine, carbon monoxide, free nicotine, and tobacco-specific nitrosamines (TSNAs). In addition to basic surveillance of key features of international cigarette brands, we will evaluate relevant policies, such as the European Union's performance standards for cigarette emissions and increase knowledge about elasticity. This research will inform regulatory decisions made throughout the world.